Robben Island is an island in Table Bay, 6.9 km (4.3 mi) west of the coast of Bloubergstrand, Cape Town. The name is Dutch for "seal island." Robben Island is roughly oval in shape, 3.3 km (2.1 mi) long north-south, and 1.9 km (1.2 mi) wide, with an area of 5.08 sq km (1.96 sq mi).It is flat and only a few meters above sea level, as a result of an ancient erosion event. Nobel Laureate and former President of South Africa Nelson Mandela was imprisoned there for 18 of the 27 years he served behind bars before the fall of apartheid. Robben Island is a South African National Heritage Site as well as a UNESCO World Heritage Site.